Software testing can be complex and expensive. One import form of testing is to test that the performance characteristics of a newer version of software is acceptable relative to the older version. When dealing with very large software, such performance testing can be very time-consuming and expensive. Such testing typically includes instrumenting the software, executing the instrumented software, and profiling the execution to determine performance characteristics such as cache misses, pages faults, and the like. Techniques for reducing performance testing costs are desirable.